Watch doesn’t go on when wrist is raised.

You have done all the preliminary troubleshooting, so we need to go further.

First force restart the Watch

i.e. press and hold both the side button and Digital Crown for at least 10 seconds, then release both buttons when you see the Apple logo.

Then, although it may seem irrelevant, Force Restart the paired iphone   Force restart iPhone – Apple Support (UK)

If is is still misbehaving...

 Unpair and erase your Apple Watch

and then

Set up your Apple Watch

 If no better you may want to unpair then set up without restoring the backup.

You may also want to make sure the software on the watch is up to date.

Update your Apple Watch

If you've completed that troubleshooting and the issue is still not resolved, Contact Support.

Click here > Contact - Official Apple Support

or phone numbers 

Click here > Contact Apple for support and service - Apple Support

In addition to what lobsterghost1 said, also check here:

From your phone, open your Watch app.

Go to Display & Brightness and make sure that "Wake on Wrist Raise" is on.

Or you can...

From your watch:

Open Settings and scroll to Display & Brightness then click on it. Next, scroll down to "Wake on Wrist Raise" and make sure it's on.

I hope that this will help you out ;-)

Did you look in Control Center as I suggested? Also, as we are all users on this user to user only forum, getting angry and threatening to buy a fitBit get's you nothing from us users. We are trying to help you using our personal time.

Swipe up from the bottom of the watch screen to open Control Center. Turn off Theater Mode (the mask faces) if it is on.